In a large mixing bowl, combine drained eggplant, peas, carrots, sweet potato, onion, egg whites, matzo meal or panko, scallions, curry, ginger, turmeric, cumin, coriander, cayenne, salt, and pepper. Stir until the mixture holds together; you may need to add a bit more matzo meal or panko if the mixture is moist. Form mixture into thick cakes.